Field of the Invention
The present invention relates to a solid-state image sensor.
Description of the Related Art
A solid-state image sensor includes a photoelectric conversion portion formed on a substrate and reads out charges generated by light which has entered this photoelectric conversion portion. Japanese Patent Laid-Open No. 2004-71817 has described the structure of a solid-state image sensor where light which has passed through a photoelectric conversion portion without being converted into charges is reflected by a reflection layer arranged under the photoelectric conversion portion and returned to the photoelectric conversion portion. As a result, efficiency of converting light which has entered the photoelectric conversion portion into charges is improved.